root

Synonyms: basis bedrock beginnings bottom cause center crux derivation essence essentiality footing foundation fountain fountainhead fundamental germ ground groundwork heart inception infrastructure mainspring marrow motive nub nucleus occasion origin pith provenance provenience quick quintessence radicle radix reason rhizome rock bottom seat seed soul source starting point stem stuff substance substratum tuber underpinning well

Antonyms: derivation derivative sprout

Synonyms: burrow delve embed ferret forage grub grub up hunt ingrain lodge nose place poke pry rummage

Antonyms: cover