Piecing

[Lizzy Liz]

Origins unknown; used as a [codeword] to describe people hooking up; now used as common slang in (mostly the north of) Scotland to describe any kind of sexual activity, and indeed many other activities which have little [or nothing] to do with sex, and is generally used to indicate that something fortunate has occurred. It can be used as a legitimate verb in regular conversation, but it is normally just shouted, and is accompanied by a hand action where one puts the thumb and middle finger together, and [taps] them with the index finger.

[Becky]

to put the parts of something into place: