the word 'stealthily' is built upon the noun 'stealth', which originates from the old english stælþ, a derivative of the verb stelan meaning 'to steal'. the core concept of 'stealth' thus evolved from the literal act of taking something secretly to the broader, abstract quality of secretive or furtive action. the adverbial suffix '-ly', of germanic origin, was attached to form 'stealthy', and the connective 'i' was inserted before '-ly' to create the adverb, following a common pattern in english word formation. therefore, 'stealthily' literally means 'in a manner characterized by secrecy', preserving the ancient link between concealment and the act of stealing.

Structure: stealth (secret) + i (connective) + ly (adverb suffix) stealth (from old english stælþ, meaning 'theft' or 'act of stealing', functioning as the core noun root); i (a connective vowel with no independent meaning, used for euphony); ly (from old english -līce, an adverbial suffix meaning 'in a manner of').