say it: HED-ing
heading is a noun meaning "a line of text serving to indicate what the passage below it is about". It carries 3 recorded senses.
a horizontal (or nearly horizontal) passageway in a mine
“they dug a drift parallel with the vein”
mining
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for heading come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.