undercount

un·der·count

U0049300 (ŭn′dər-kount′)tr.v. un·der·count·ed, un·der·count·ing, un·der·counts To record fewer than the actual number of (persons in a census, for example).
un′der·count′ n.

undercount

(ˈʌndəˌkaʊnt) n (Statistics) statistics an incomplete count

un•der•count

(v. ˌʌn dərˈkaʊnt; n. ˈʌn dərˌkaʊnt)
v.t. 1. to count less than the full number or amount of, esp. in an attempt to falsify records, returns, etc. n. 2. a count or total that is less than the actual number or amount. [1950–55]