The spelling <close> can mean three different things:
1. A verb meaning “to shut”. The pronunciation is kləʊz. The same is true of the derivation disclose.
2. An adjective meaning “near”. The pronunciation is kləʊs. The addition of an inflectional ending makes no difference, so for example closer = ˈkləʊsə, and closely = ˈkləʊsli.
3. A noun meaning “enclosed space”. The pronunciation is kləʊs.