This is the definition of aquatint: (Go to Wikepidea for more)
Aquatint is an intaglio printmaking technique, a variant of etching that produces areas of tone rather than lines. For this reason it has mostly been used in conjunction with etching, to give both lines and shaded tone.
Or, If you meant acquaintance, It's like a person you just met, or someone you don't know very well.
Hope this helps!