凌云 is a literary verb-object compound meaning 'to soar to the clouds' or 'to reach the clouds'. It is almost always used figuratively to describe lofty ambition or majestic spirit, most famously in the idiom 壮志凌云 ('with soaring aspirations'). As a separable verb (离合词), you can insert 了, 过, or a measure word like 次 between 凌 and 云 (e.g., 凌过云 'have soared through the clouds'), though in practice the split form is rare and the word is usually treated as a single unit. It is a high-register, poetic expression; you won't use it in everyday conversation.