In this sentence "já" means "already". The full dictionary definition from Wiktionary:
(usually preceding verbs in the past tense) already (indicating that something has happened before)
(usually following verbs in the present tense) now (at this instant)
(in negative sentences, preceding the adverb não) anymore; any longer
(usually preceding verbs in the present tense) in a minute; soon
(preceding noun phrases) on the other hand
Usage notes: In Portuguese, já is said more frequently than the English equivalents. It is sometimes left untranslated altogether.