confront, resist, defy, oppose
抗 centers on pushing back against something: confronting, resisting, defying, or opposing a force or idea.
抗 combines 扌 (hand) with 亢, which likely contributes the sound and the idea of raising or resisting. The hand component suggests physical opposition.
The hand radical 扌 beside 亢 looks like a hand raised to push back. Imagine using your hand to resist and confront an opponent.
For コウ, picture a hand raised in opposition during a heated debate, like a coach shouting "Kō!" to signal defiance: Kō -> コウ.
resistance; opposition; standing up to
opposition; rivalry; competition; antagonism
protest; objection
anti-
opposition; resistance; insubordination; defiance; hostility; rebellion
antibiosis
rivalry; feud; conflict; dispute; struggle; strife; contention; resistance
antibody
antibacterial; antimicrobial
rivalry (between two equally strong sides); struggle for supremacy; competing (with); vying (with); contending (with); being an equal match (for)
to go against; to fight against; to oppose; to resist; to deny
antigen
resistance
act of God; irresistible force; inevitability
resistance against Japanese aggression; anti-Japanese (campaign, movement, etc.)
appeal; protest; complaint
protest; refutation; pleading
anticancer drug; anticancer agent
to resist; to defy
antihistamine