possibly UK /ˈpɒs.ə.bli/US /ˈpɑ.sɪ.bli/ adverb2 •perhaps, showing there is a chance that something is true or will happenPossibly, they will make gains in the midterm elections.It was possibly the costliest mistake in the organization's history. •In the realm of possibility; indicates that the action may successfully be performed (is not impossible) regardless of any facts or circumstances known to, stated by or implied by the speaker that might limit the performance.I'm much stronger than you, so you can't possibly win.I couldn't possibly be there on time. formsmore possibly · most possibly