orig. U.S.

Of no account, importance, value, or use; insignificant, worthless. (See also no-'count a.)
1845 Spirit of Times 1 Feb. 583/2 I'll just tell you that the land I'm after is a d-d, little, no-account quarter section, that nobody would have but me. 1886 Pall Mall Gaz. 29 Sept. 4/1 We submit to be+treated as no-account people in all affairs of State. 1898 H. S. Canfield Maid of Frontier 109 It seems to me+that Charlie is gettin mighty no account. 1900 Conrad Lord Jim v. 47 The other two no-account chaps spotted their captain, and began to move towards us. 1902 G. H. Lorimer Lett. Merchant vi. 69 A mailing-clerk so no-account as to be writing personal letters in office hours. 1936 ‘J. Tey’ Shilling for Candles v. 51 ‘You mean she thinks he's a wrong 'un?’ ‘No. Just no account.’ Ibid. vii. 71 We both felt no-account and were afraid people'd find it out. 1952 C. Day Lewis tr. Virgil's Aeneid xi. 246 Are we, we no-account souls, to litter the plains? 1973 M. Mackintosh King & Two Queens xii. 180 I'm only a no-account Irisher, but I like to pay my debts.

B. n. A ‘no-account’ person.
1896 ‘Mark Twain’ in Harper's Mag. Sept 523 Who ever had anything agin that poor trifling no-account? 1936 J. Dos Passos Big Money 169 The child of a no-account like Fred.
[OED2]