what's the matter?; what's wrong?; what happened (to) ...?; what have you done (with) ...?; where is ...?
top and bottom; high and low; going up and down; rising and falling; going and coming back; upper and lower classes
stroboscope; strobe lamp; stroboscopic lamp; (camera) flash
space; interval; space character; whitespace
to illuminate; to shine a light on; to light up
in name only; figurehead; (only) by name
honor; honour; glory; (arch.) prosperity
distress; wretched condition
pensive (or worried) look on one's face
one's field of expertise; one's strong area
ancient civilization; ancient civilisation
ingredient; component; composition
trip; excursion; (drug) trip; tripcode
continuous; nonstop; consecutive; ceaseless
to boil up; to come to the boil; to arise; to break out; to get excited; to be in uproar
indicates concession or compromise; indicates permission
fate; destiny; predestination
the other day; lately; recently
carefree; comfortable; at ease; easygoing; happy-go-lucky
tool (esp. software, etc.); tour (e.g. Tour de France)
rehabilitation; reinstatement; restoration of rights
corridor; gallery; hallway; cloister (i.e. covered walk typically circling a building or garden, esp. in a palace or place of worship)
awkward; embarrassed; embarrassing; inconvenient; inopportune; untimely
to support; to prop; to sustain; to hold at bay; to stem; to check
research establishment; research institute; laboratory
to maintain; to continue to have
cancer causing; carcinogenesis
extempore; impromptu; improvised; ad-lib; off-the-cuff; instant
to pull up; to drag up; to increase; to raise (e.g. taxes); to withdraw; to leave; to promote (someone to a higher position)
(around the) neck; nape; collar (at the front)
double; twice (as much); twofold
to screw in; to thrust into; to push into; to protest (and seek rectification); to complain
good contrast; marked contrast
(just) out of curiosity; (just) in order to satisfy one's curiosity; aimed chiefly at amusing; sensational (e.g. magazine)