say it: FAL-oh
fallow is an adjective and noun meaning "left unplowed and unseeded during a growing season". It carries 3 recorded senses.
cultivated land that is not seeded for one or more growing seasons
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 fallow 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.