The word 足以 is formed by combining the character 足, which originally meant "foot" but carries the abstract sense of "sufficient" or "adequate", with the character 以, a versatile particle that often denotes "by means of" or indicates a purpose or result. Their fusion creates a single unit where 足 provides the core meaning of "enough" and 以 directs that sufficiency toward an action or outcome, conceptually forming the idea of "sufficient to" or "adequate for" accomplishing something.