Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
snarl-up is a noun meaning "a number of vehicles blocking one another until they can scarcely move". It carries one recorded sense.
a number of vehicles blocking one another until they can scarcely move
Definitions, synonyms and semantic relations for snarl-up come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.