to add (something) as an extra part; to append
to incorporate (a country or other territory) within the domain of a state
to attach (something) as a consequence or condition
to take or use (something), esp without permission
The true artist is known by the use he makes of what he annexes — Oscar Wilde
annexable adj
annexation /anekʹsaysh(ə)n/ noun
annexationist /-ʹsaysh(ə)nist/ noun and adj
[Middle English annexen via Old French from Latin annexus, past part. of annectere to bind to]