VANGUARD

vanguard, forefront, cutting edge

(noun) the position of greatest importance or advancement; the leading position in any movement or field; “the Cotswolds were once at the forefront of woollen manufacturing in England”; “the idea of motion was always to the forefront of his mind and central to his philosophy”

vanguard, van

(noun) the leading units moving at the head of an army

vanguard, avant-garde, van, new wave

(noun) any creative group active in the innovation and application of new concepts and techniques in a given field (especially in the arts)

Source: WordNet® 3.1

Etymology

Noun

vanguard (plural vanguards)

(military) The leading units at the front of an army or fleet.

Synonyms: advance guard, avant-garde (obsolete)

Antonym: rearguard

(by extension) The person(s) at the forefront of any group or movement.

Synonym: avant-garde

Source: Wiktionary

Van"guard`, n. Etym: [For vantguard, avantguard, F. avant-garde; avant before, fore + garde guard. See Avant, Ab-,Ante-, and Guard, and cf. Advance, Vamp, Van of an army, Vaward.] (Mil.)

Definition: The troops who march in front of an army; the advance guard; the van.

Source: Webster’s Unabridged Dictionary 1913 Edition