say it: WEST-bownd
westbound is an adjective meaning "moving toward the west". It is pronounced /ˈwɛstˌbaʊnd/ — WEST-bownd. It carries one recorded sense.
Forms marked are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for westbound come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.