I had never come across the word before but apparently a hypothecated tax is one in which ring-fenced funds are collected by taxation to pay for a specific government expenditure. This kind of tax is being suggested in the UK in order to fund the National Health Service in the future.
The OED appears to be defining the verb 'hypothecate' in a way that is definitely different in meaning to 'hypothetical' :
- trans. To give or pledge as security; to pledge, pawn, mortgage.
'Hypothetical' is from 'hypothesis' which the OED tells me comes from Greek : ὑπό under + θέσις placing. So a hypothesis is an argument 'placed under' a statement.
The OED gives the etymology of 'hypothecate' as :
hypothēcāt-, participial stem of medieval Latin hypothēcāre , < hypothēca hypothec n.: see -ate suffix3. Compare French hypothéquer.
But this all seems a bit muddled to me both in the origin (would not 'hypothecate' have a Greek etymology, intially ?) and in the present English meaning (is not the ring-fenced tax an opposite of a hypothetical tax ?).
It is especially odd when the OED then offers a second meaning for 'hypothecate' as :
- trans. = hypothesize v. 2.
thus implying either the same origin or the same meaning for the word as 'hypothetical'.
Any help would be appreciated.