Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
across-the-board is an adjective meaning "broad in scope or content". It carries one recorded sense.
broad in scope or content
“across-the-board pay increases”
“an all-embracing definition”
“blanket sanctions against human-rights violators”
“an invention with broad applications”
“a panoptic study of Soviet nationality”
“granted him wide powers”
Definitions, synonyms and semantic relations for across-the-board come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.