conceivable
adj.possible to imagine or believe. You use this to describe something that could happen, even if it is unlikely.
adj.capable of being imagined or grasped mentally. Often used to emphasize the range of possibilities, frequently following 'every' or 'any'.
“It is conceivable that we will finish the project early.”
“The team explored every conceivable solution to the technical problem before deciding to start over.”
“While a peaceful resolution remains conceivable, the escalating rhetoric from both sides suggests that a diplomatic breakthrough is increasingly improbable in the current political climate.”
Often used in the superlative sense with 'every' ('every conceivable way') or following 'it is' as a modal hedge.
From conceive + -able.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.