(past could; present singular & plural can)
Etymology: Middle English (1st & 3d singular present indicative), from Old English; akin to Old High German kan (1st & 3d singular present indicative) know, am able, Old English cnāwan to know — more at know
Date: before 12th century
1. obsolete know, understand
2. archaic to be able to do, make, or accomplish
archaic to have knowledge or skill
a. know how to <she can read> b. be physically or mentally able to <he can lift 200 pounds> c. — used to indicate possibility <do you think he can still be alive> <those things can happen> — sometimes used interchangeably with may d. be permitted by conscience or feeling to <can hardly blame her> e. be made possible or probable by circumstances to <he can hardly have meant that> f. be inherently able or designed to <everything that money can buy> g. be logically or axiologically able to <2 + 2 can also be written 3 + 1> h. be enabled by law, agreement, or custom to 2. have permission to — used interchangeably with may <you can go now if you like> Usage: Can and may are most frequently interchangeable in senses denoting possibility; because the possibility of one's doing something may depend on another's acquiescence, they have also become interchangeable in the sense denoting permission. The use of can to ask or grant permission has been common since the 19th century and is well established, although some commentators feel may is more appropriate in formal contexts. May is relatively rare in negative constructions (mayn't is not common); cannot and can't are usual in such contexts. II. noun Etymology: Middle English canne, from Old English; akin to Old High German channa Date: before 12th century 1. a usually cylindrical receptacle: a. a vessel for holding liquids; specifically a drinking vessel b. a usually metal typically cylindrical receptacle usually with an open top, often with a removable cover, and sometimes with a spout or side handles (as for holding milk or trash) c. a container (as of tinplate) in which products (as perishable foods) are hermetically sealed for preservation until use d. a jar for packing or preserving fruit or vegetables 2. jail 3. a. toilet b. bathroom 1 4. buttocks 5. destroyer 2 • canful noun III. transitive verb (canned; canning) Date: 1859 1. a. to put in a can ; preserve by sealing in airtight cans or jars <can tomatoes> b. to hit (a golf shot) into the cup c. to hit (a shot) in basketball 2. to discharge from employment 3. slang to put a stop or end to • canner noun IV. abbreviation 1. canceled; cancellation 2. cannon 3. canto
New Collegiate Dictionary. 2001.