rubber stamp

1. a stamp () made of rubber, pressed on an inking pad and used for printing signatures, dates, emblems, etc.
2. ☆ Informal
   1. a person, bureau, legislature, etc. that approves or endorses something in a routine manner, without thought
   2. any routine approval

transitive verb

1. to put the impression of a rubber stamp on
2. ☆ Informal to approve or endorse in a routine manner, without thought

adjective