Verb
(transitive, idiomatic) To publicly support (someone).
(transitive, idiomatic) In a wedding ceremony, to serve as best man or as maid of honor or as an official witness for (someone).
(transitive, idiomatic, archaic) To begin to dance with (someone); to dance with (someone).
Source: en.wiktionary.org“Industry is starting to stand up with a lot of the commercial satellites,” said Maj. Janelle Jenniges, Air Force Space Weather Integration chief. Source: Internet
"I'm going to go out there and stand up with him because that's what everyone wants to see. Source: Internet