1 (wiktionary) 2 (de.wikipedia) 3 (en.wikipedia) 4 (glosbe)

Verbs Nouns Adjectives/Adverbs Pronouns Prepositions Conjunctions
occasion (Advanced search)

CEFR GNOT Temporal • frequency occasional(ly)
CEFR GNOT Temporal • intermittence occasionally

NGSL3000 occasion time when something happens or takes place n
NGSL3000 occasionally not very often; sometimes; seldom adv
SAT5000 occasion An important event or celebration. n.

Tanaka6000 occasion Tanaka6000 occasionally Tanaka6000 occasions

occasion {n} (favorable opportunity) occasion {n} (happening) occasional {adj} (limited to certain occasions; not very often) occasionally {adv} (from time to time; now and then; once in a while; at infrequent intervals) occasional table {n} (small table having no particular function)

Let's reserve that for another occasion .	Lassen Sie uns das für einen anderen Anlass reservieren.
I never have had occasion to use it .	Ich hatte nie Gelegenheit, es zu benutzen.
They visited me occasionally .	Sie besuchten mich gelegentlich.
I've met him on several occasions .	Ich habe ihn mehrmals getroffen.