have (or show) boldness or initiative - British informal
The mid 19th-century slang phrase no bottle meaning no good or useless is the probable origin of bottle's current sense of courage or nerve. Nowadays we also find the expressions lose your bottle meaning lose your nerve and bottle out meaning fail to do something as a result of losing your nerve.
Related Idioms and Phrases :
hit the bottle = be on the bottle
start to drink alcohol heavily especially in an attempt to escape from one's problems - informal