v.

1. lose velocity; move more slowly;
   decelerate, slow down, slow up, retard
   
   • The car decelerated
2. become slow or slower;
   slow down, slow up, slack, slacken
   
   • Production slowed
3. cause to proceed more slowly;
   slow down, slow up
   
   • The illness slowed him down

adj.

1. not moving quickly; taking a comparatively long time
   
   • a slow walker
   • the slow lane of traffic
   • her steps were slow
   • he was slow in reacting to the news
   • slow but steady growth
2. at a slow tempo
   
   • the band played a slow waltz
3. slow to learn or understand; lacking intellectual acuity;
   dense, dim, dull, dumb, obtuse
   
   • so dense he never understands anything I say to him
   • never met anyone quite so dim
   • although dull at classical learning, at mathematics he was uncommonly quick"- Thackeray; "dumb officials make some really dumb decisions
   • he was either normally stupid or being deliberately obtuse
   • worked with the slow students
4. (used of timepieces) indicating a time earlier than the correct time
   
   • the clock is slow
5. so lacking in interest as to cause mental weariness;
   boring, deadening, dull, ho-hum, irksome, tedious, tiresome, wearisome
   
   • a boring evening with uninteresting people
   • the deadening effect of some routine tasks
   • a dull play
   • his competent but dull performance
   • a ho-hum speaker who couldn't capture their attention
   • what an irksome task the writing of long letters is"- Edmund Burke; "tedious days on the train
   • the tiresome chirping of a cricket"- Mark Twain; "other people's dreams are dreadfully wearisome
6. (of business) not active or brisk;
   dull, sluggish
   
   • business is dull (or slow)
   • a sluggish market

adv.

1. without speed (`slow' is sometimes used informally for `slowly');
   slowly, easy, tardily
   
   • he spoke slowly
   • go easy here--the road is slippery
   • glaciers move tardily
   • please go slow so I can see the sights
2. of timepieces;
   behind
   
   • the clock is almost an hour slow
   • my watch is running behind