Full Idea
We shall say we have 'acquaintance' with anything of which we are directly aware, without the intermediary of any process of inference or any knowledge of truths.
Gist of Idea
'Acquaintance' is direct awareness, without inferences or judgements
Source
Bertrand Russell (Problems of Philosophy [1912], Ch. 5)
Book Reference
Russell,Bertrand: 'The Problems of Philosophy' [OUP 1995], p.25
A Reaction
Although Russell understands the difficulty of precise distinctions here, he implies that some knowledge is directly knowable, although truth only enters at the stage of judgement. Personally I would suggest that pure acquaintance is not knowledge.