on offer	being offered especially for sale
on purpose	intentionally
beyond a joke	nothing funny
beyond the shadow of a doubt	certain
by rights	legally or with reason
for fear of	because sth might happen
for the time being	temporary
out of doors	outside
out of luck	unlucky
out of pocket	not to have money
out of work	jobless
under the cover of darkness	at night, secretly, furtively
under suspicion	suspected
on behalf of	in the interest of/ as a representative of