o‧ver‧lap1 past tense and past participle overlapped, present participle overlapping [intransitive and transitive]
if two or more things overlap, part of one thing covers part of another thing:
One of Jilly's front teeth overlaps the other.
The tiles on the roof overlap.
if two subjects, ideas etc overlap, they include some but not all of the same things:
Maxwell's responsibilities overlap yours, so you will be sharing some of the work.
The study of sociology overlaps with the study of economics.
two great men with overlapping interests
if two activities or periods of time overlap, the second one starts before the first one has finished:
The second phase of development overlaps the first.
My vacation overlaps with yours.