1. mailgram - Noun
2. mailgram - Verb
mailgram (plural mailgrams)
(telegraphy) A telegraphic message transmitted electronically from the sender to a post office and then printed and delivered to the recipient via physical post.
(transitive, rare) To send by mailgram.
(transitive, rare) To send a mailgram to.
Source: en.wiktionary.org