From Hull AWE
- Acquaintance has two main strands of meaning in current English.
- As a count noun, it means 'a person whom one knows [not intimately nor well]'. 'A nodding acquaintance' is someone to whom one might nod one's head when seeing them on campus or in the street, but with whom one would make no particular effort to talk. (In older English, until the seventeenth century, it seems to have implied a greater intimacy, even friendship.) This meaning can be used uncountably in such phrases as 'she had a large circle of acquaintance' to mean 'all of the people whom one knows, but whom one would not count as friends'. Jane Austen wrote in Emma (1816): "The acquaintance she had already formed were unworthy of her" (I. iii. 42, cited OED).
- As a non-count noun, acquaintance is akin to knowledge: a student may have an acquaintance with one aspect of the subject. Here the word does not imply casual or superficial knowledge: a professor may have an abiding deep acquaintance with a subject after years of concentrated study.
- 'To acquaint [someone with something]' is to inform him of it, to tell him about it. It is rarely used these days for 'to introduce someone to somebody'. A professor may acquaint a student with the outlines of a new topic.
- Isaiah, 53:3, in the AV, prophesies the messiah as "... despised and rejected of men; a man of sorrows, and acquainted with grief."
This is one of the 117 mis-spellings listed as 'Common difficulties' in the section on 'Spelling' within 'Writing' in UEfAP.