1.
When you send off a letter or package, you send it somewhere by post.
He sent off copies to various people for them to read and make comments.
PHRASAL VERB : V P n (not pron) , also V n P
2.
If a football player is sent off , the referee makes them leave the field during a game, as a punishment for seriously breaking the rules.
The 30-year-old Scottish international was sent off for arguing with a linesman.
PHRASAL VERB : usu passive , be V-ed P
see also sending-off