TOPSY-TURVY

21 swapwords:

1 takeover / overtake
2 offset / set-off
3 night-watch / watch-night
4 gunshot / shotgun
5 long-life / lifelong
6 boathouse / houseboat
7 outlook / lookout
8 payback / backpay
9 fall-back / backfall
10 takeout / outtake
11 phonecard / cardphone
12 line-out / outline
13 schoolday / day-school
14 turnover / overturn
15 layout / outlay
16 setback / backset
17 uptake / take-up
18 sleepover / oversleep
19 punch-card / cardpunch
20 break-out / outbreak
21 upset / set-up

A Swapword is a compound word where the first and last parts can be swapped to make a new word. Both words must be whole or hyphenated, not phrases. I have gone along with Chambers' definitions on whether swapword candidates are one word, two or have a hyphen. There are surprisingly few. If you know any others let me know - check a dictionary first.

Source: RcL