I. phrasal
1.
a. : capable of performing or dealing with : competent or able to cope with : capable of
feels she is up to her role in the play
is now up to seeing visitors
was up to doing the job in a little over six days — Robert Bendiner
specifically : capable of carrying without strain
require a horse up to 13 stone — F.C.Hitchcock
b. : aware of and prepared for
should certainly be up to his tricks by this time
2. : engaged in especially secretly and with intentions that are bad or not altogether good
ferreting out clues as to what he was up to — R.H.Popkin
was always up to something — H.G.Wells
3. : incumbent on : devolving on : being the responsibility of
it was up to the parent to educate his child — Benjamin Fine
left the next move up to the Russians — Current History
the amount you give is entirely up to you — Agnes M. Miall
II. preposition
Etymology: Middle English
1. : as far as a designated part (as of the body or a weapon that penetrates)
sank in quicksand up to his armpits
pushed the knife in up to the hilt
was walking right into hot water … up to her neck — Elizabeth Headley
2. : to or in fulfillment of : in complete accordance with : so as to make full use of
unable to write up to their high standards
practices up to his knowledge
3.
a. : to the limit of
guesses on the size of his wealth ran up to $2 billion — Joseph Nolan
sick leave may be accumulated up to 150 days — Careers for College Graduates
golden perch, up to a few pounds in weight, bit readily — Francis Birtles
come in sizes up to 10 cups — Jane Nickerson
b. : as many as : as much as
freighters carry up to 12 passengers — Richard Joseph
would exempt tickets costing up to 60 cents — Wall Street Journal
carelessness may mean great agony and up to weeks in bed — J.L.B.Smith
4. : till , until
up to that date they had been generally successful — American Guide Series: Michigan
up to the war rural areas were always the dwelling place of the surplus population — S.E.Harris
5. : as far as a designated point
painted the wall green up to the side door
up to this point we have discussed chiefly the material factors — W.C.Huntington