comfortable, comfy (informal), cushioned, padded, plush, soft, upholstered
hard, uncomfortable
deep, low
high-backed, straight-backed, wing-backed, winged
rickety
reclining, rocking, swivel
He lay back in the reclining chair and went to sleep.
She sat down in the swivel chair behind her desk.

folding
matching
a dining table and four matching chairs

empty
He gestured to an empty chair.

antique
leather, metal, plastic, steel, wicker, wooden, etc.
dining, kitchen, lounge (esp. AmE)
computer, desk, office
beach (esp. AmE), garden (esp. BrE), lawn (esp. AmE)

row
set
a set of antique dining chairs

draw up, pull up
‘Can I join you?’ ‘Yes, pull up a chair.’

pull out
He pulled out a chair for her.

grab, have, take
Come in and take a chair.

give sb
He gave her his chair.

push back
He pushed back his chair and got to his feet.

collapse into/onto, flop (back/down) in/into/on/onto, lower yourself into, settle (back) in/into/on, sink (back/down) into, sit (down) in/on, slump (back/down) in/into
She dropped her bags and flopped down into the nearest chair.

lean back in, lie back in, lounge (back) in, recline (back) in, relax (back) in
He put his feet up on the desk and lay back in his chair.

be sprawled in, sprawl in
lean forward in
straighten (up) in
They straightened in their chairs when the manager burst in.

get out of, get up from/off, jump (up) from/out of, leap out of/from, rise from
He got up from his chair to address the meeting.

rock backwards and forwards in/on, shift about in (BrE), shift in, tip back
He was shifting about uneasily in his chair.
She tipped her chair back and fixed her gaze full upon him.

swivel, swivel (around) in, swivel on
She always swivels around in her chair.

be placed, stand
A chair stood facing the window.

swivel
tip back
fall over, topple over
creak
The chair creaked every time I moved.

scrape sth, scrape against sth, scrape along sth
Lisa heard a chair scraping the floor.

arm, back, leg, seat
cover, frame

into a/the chair
He sank into his chair and opened the letter.

in a/the chair
She leaned back in her chair and lit a cigarette.

on a/the chair
A cat was asleep on the chair.

the arm of a chair, the back of a chair, the edge of a chair, the leg of a chair
She gripped the arm of her chair as she spoke.
He sat nervously on the edge of his chair.

acting, deputy
honorary

occupy, take (both esp. BrE)
Anne took the chair (= was chairperson) in Carol's absence.

address (sth to)
Please address your questions to the chair.

appoint sb (as), elect sb (as)

in the chair (esp. BrE)
Paul Ryan was in the chair (= was chairperson) at today's meeting.

professorial

hold, occupy
He held the Chair of Psychology at Yale.

appoint sb to
resign
endow, establish
A private benefactor endowed the new Chair of Japanese Literature.