Source : Webster's Revised Unabridged Dictionary (1913)

Straightness \Straight"ness\, n.
   The quality, condition, or state, of being straight; as, the
   straightness of a path.

Straightness \Straight"ness\, n.
   A variant of {Straitness}.

Source : WordNet®

straightness
     n 1: of hair: lack of a tendency to curl [ant: {curliness}]
     2: freedom from crooks or curves or bends or angles [ant: {crookedness}]
     3: trueness of course toward a goal; "rivaling a hawk in
        directness of aim" [syn: {directness}] [ant: {indirectness}]
     4: having honest intentions; "he acted in good faith"; "doubt
        was expressed as to the good faith of the immigrants"
        [syn: {good faith}]
     5: a sexual attraction to (or sexual relations with) persons of
        the opposite sex [syn: {heterosexuality}, {heterosexualism}]