The word pasang “pair/couple” is a noun and usually refers to a male and a female:

Dua pasang suami istri.
Two married couples.

Bambang membeli dua pasang burung dara.
Bambang buys two pairs of pigeons.

Pasang also refers to inanimate objects that come in pairs such as shoes, socks, wings (but not – as in English – trousers/pants, scissors, or spectacles/eyeglasses).

Saya membeli tiga pasang sepatu.
I buy three pair of shoes.

Pasang can also denote a set:

Dewi membeli dua pasang meja kursi sekaligus.
Dewi bought two sets of tables and chairs at once.

A pasangan is something/someone that is coupled/the other part of a pair:

Di mana pasangan sepatu itu?
Where is the other shoe?

Rudi pasangan menarimu?
Is Rudi your dancing partner?

Akiko dan Joe sudah menjadi pasangan.
Akiko and Joe are a couple now.

Most interesting, and most challenging, is the verb memasang, which basically means “to pair”,  “to match”, or “to fit” , and hence also “to install”.

Dia memasang ac di rumah. He installed an air-conditioning unit in his house.
Besok saya harus memasang ban baru. Tomorrow I have to put on new tires.
Saya memasang bintang penghargaan di dadanya. I pin the medal on his chest.
Jangan lupa memasang bola lampu. Don’t forget to fit the light bulb.

Here are more examples. Note that the underlying idea is always that two things are matched to another (like the curtain is matched with the rod, the printer with the computer, the advertisement with the media in which it is placed, the fire to the candle, etc.)

memasang lilin, to light a candle
memasang api, to light a fire
memasang sepatu, to put on shoes
memasang tali sepatu, to tie one’s shoes
memasang printer, to connect a printer
memasang gorden, to hang up curtains
memasang iklan, to place an advertisement.
memasang kemah, to set up a tent
memasang kancing, to button up
memasang tellinga, to sharpen one’s ears, listen carefully
memasang mesin to install a machine
memasang pakaian, to put on clothes
memasang saluran tivi, to turn on a television channel
memasang pagar, to build a fence
memasang bendera, to hang out the flag
memasang layar, to set sails
memasang tarif/harga, to set a fare/price
memasang pengumuman, to post an announcement
memasang radio, to turn on the radio
memasang aksi, to show off
memasang taruhan, to place a bid

This word is difficult to find in the dictionaries because the “proper” form is actually “gemas”. Gemes is the Jakartanese pronunciation. The word describes the emotion of intense and passionated anger, but the way you will mostly encounter it in Indonesian is in one set phrase (which you will quite frequently hear): “Gemes aku melihat anak itu”.
“In India, it’s common for strangers to pinch a child’s cheek.”
(Mathangi from Mumbai)
Why would you feel passionated anger towards a cute little child? Well, this is precisely the nature of gemes: The passion that you feel can also be one of strong love, affection, motherly feelings, or a combination of emotions that overwhelms you when you see such a cute little thing. In English we have a very similar expression, which also combines strong love with the desire to destroy the object of your love: “I like her so much, I could eat her up”.

This very strong emotion often causes Indonesian women (more than men) to approach such a child and pinch that child’s cheek. The children do not necessary find this funny, and when the child of one of my friends in Indonesia (a native German) started to cry after having been pinched excessively, my German friend took revenge by strongly pinching that baby-pinching woman into her own cheek! Outch.

Cheek-pinching may even be a pan-Asiatic sport. At least this account from Indiamike.com seems to confirm this:

“My son had been in India nearly 3 years (arrived age 2), and gets his cheeks pinched – by strangers and people who know him – all the time. This never happened back home in Europe. He’s pretty much used to it but sometimes it hurts and he ends up crying – he’s even been bruised and a lady’s sharp nails once drew blood.  So I want to know – if you’re a cheek pincher – do you know why people do this? is it all children or ones with particularly juicy looking cheeks!?”
Someone else followed up this entry, writing:

“We travelled with both our daughters through SE Asia (mainly Thailand, Malaysia) when they were toddlers and they were constantly having their cheeks pinched. [...] Eventually they came to hate it and would cover their faces when people came rushing towards them. Is your son very fair? My two were both blonds and that seemed to attract people like magnets! I think it’s meant to be affectionate but I guess when you’re the fortieth person to do it that day, it gets really intrusive for a young child.

An Indian lady followed up, explaining:

“In India, it’s common for strangers to pinch a child’s cheek, try to pick it up, pat a kid’s head or try to lift the kid up. Mind you, most of us come from big families with lots of children running around and nobody has any bad intentions.”

So why do strangers approach someone else’s child to pinch her cheeks? It is because they feel gemes, which in the KBBI is described as “sangat suka bercampur jengkel” (a feeling of strong love mixed with annoyance).

Click on the link to see a photo of a child “yang bikin gemes dan lapar” (that makes me feel gemes and hungry)

“Pak Bei” is almost complete, and will be integrated into the curriculum during the academic year 2012.