Comes from the work “Smacked” as in waisted, drug, or not sober.

Someone who is always under the influence of a controlled substance. Also another name for a drug abuser.
That kid is always under the influence of something. Cannot ever stay sober. Such a Shmackhead
by The Hood Dictionary May 16, 2018
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Ayo my drilla my dads uncles brother grandson is shmackhead steve
by Clapped2.0 August 5, 2022
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A person who in never sober. Always under the influence of drugs or alcohol. Also a complete dumb ass who takes drugs.
That guy who chugged a bottle up his ass is a shmackhead. #503kSlang
by The Hood Dictionary May 16, 2018
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