This is an old-fashioned word which starches any letter in which it is used as a synonym for think. But it is still useful in its technical sense of signifying the constructive or inferential as opposed to the explicit or actual.
"Everyone is deemed to have intended the natural and probable consequences of his actions"
"anyone who does not give notice of objection within three weeks will be deemed to have agreed"
"any expenditure incurred in the preparation of plans for any work shall be deemed to be included in the expenditure incurred in carrying out that work."
Almost every Act of Parliament bids us deem something to be what it plainly is not. (Lord Macmillan in The Sunday Times, 14th August, 1949.)