say it: SUHB-ing
subbing is a noun meaning "working as a substitute for someone who is ill or on leave of absence". It carries one recorded sense.
working as a substitute for someone who is ill or on leave of absence
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 subbing 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.