WordNet sense 1 (a person who is frequently in the company of another):

associate, companion, comrade, fellow, associate

WordNet sense 2 (a spirit (usually in animal form) that acts as an assistant to a witch or wizard):

familiar spirit

WordNet sense 3 ((usually followed by `with') well informed about or knowing thoroughly):

conversant

WordNet sense 4 (having much knowledge or education):

informed

WordNet sense 5 (commonplace and ordinary):

everyday

WordNet sense 6 (commonly encountered):

common, usual

WordNet sense 7 (having fair knowledge of):

acquainted

WordNet sense 8 (having mutual interests or affections; of established friendship):

intimate, intimate

WordNet sense 9 (close in relevance or relationship):

close