(written) contract; agreement; contract document

signature / digital signature

to sign

a printing stamp used as a form of signature; a seal

to forget / (auxiliary verb, after the continuative form of a verb) to forget to …

indicates that something undesirable was done or happened

to close / to finish, do something completely / to put away, to put an end to / is, or was (with conjugation), done completely / happens, or happened, unexpectedly / is done with difficulty

traditional folk song of Amami / (more broadly) traditional folk song of Okinawa

To do something completely (unintentionally); cannot help doing

used in response to a failure or mistake: dang, shoot, darn it