Oh I love this! It's similar to "all bark, no bite" Basically, this person (presumably a male) talks quite a lot about how great/brave/daring they are but they have never proven it! So if someone says to you all the time that they totally go jumping off cliffs into the water all the time for fun, but never shows pictures or doesn't do so when you guys go swimming together, you'd say they are all talk but they aren't really brave like they say... so they don't really wear the trousers XD (Trousers are typically referred to in British culture as a manly thing... like "she wears the trousers in their house." could be equated to "she's the man of the house")

We use a very basic pattern when we ask about definitions: "What does ___________ mean?" We don't change it! :) So to correct your question: What does [the expression "to be all talk and no trousers"] mean?

enseñame Spanish English I teach you can add me to fb Michael Jershon Valdez Zurita