The Collaborative International Dictionary of English v.0.48:

Straightforward \Straight`for"ward\, a.
   Proceeding in a straight course or manner; not deviating;
   honest; frank. -- adv. In a straightforward manner. --
   Straight`for"ward*ly, adv. -- Straight`for"ward*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

straightforward
    adj 1: free from ambiguity; "a straightforward set of
           instructions"
    2: without evasion or compromise; "a square contradiction"; "he
       is not being as straightforward as it appears" [syn:
       square(a), straightforward, straight]
    3: without concealment or deception; honest; "their business was
       open and aboveboard"; "straightforward in all his business
       affairs" [syn: aboveboard, straightforward]
    4: pointed directly ahead; "a straightforward gaze"

Moby Thesaurus II by Grady Ward, 1.0:

178 Moby Thesaurus words for "straightforward":
   Attic, Ciceronian, Mickey Mouse, Spartan, aboveboard, apparent,
   artless, ascetic, austere, bald, bare, barefaced, bluff, blunt,
   broad, brusque, candid, casual, chaste, classic, clean-cut, clear,
   clear as crystal, clear as day, clear-cut, coherent, common,
   commonplace, connected, consistent, crisp, crystal-clear,
   crystalline, cushy, dead, dead ahead, defined, definite, direct,
   directly, distinct, downright, dry, due, due north, dull, easy,
   easy as pie, effortless, elegant, evident, explicit, express,
   facile, finished, forthright, frank, frankhearted, free,
   free-speaking, free-spoken, free-tongued, genuine, glib, graceful,
   gracile, heart-to-heart, homely, homespun, honest, honorable,
   immediate, in a beeline, in line with, inartificial, incomplex,
   ingenuous, irreversible, just, lean, light, limpid, loud and clear,
   lucid, luminous, manifest, matter-of-fact, native, natural, neat,
   nothing to it, one-way, open, openhearted, outspoken, painless,
   palpable, patent, pellucid, perspicuous, plain, plain dealing,
   plain-speaking, plain-spoken, polished, prosaic, prosing, prosy,
   pure, refined, restrained, right, round, rustic, severe, simple,
   simple as ABC, simple-speaking, sincere, smooth, sober, soft,
   spare, stark, straight, straight across, straight ahead,
   straight-out, straightaway, straightforwards, straightly,
   straightway, tasteful, terse, through, translucent, transparent,
   transpicuous, trim, unadorned, unaffected, unambiguous,
   unartificial, unassuming, unbroken, unburdensome, unchecked,
   uncomplicated, unconcealed, unconfused, unconstrained, undeviating,
   undeviatingly, undisguised, undissembled, undissembling,
   unequivocal, unfeigning, unguarded, unidirectional, unimaginative,
   uninterrupted, uninvolved, univocal, unlabored, unmistakable,
   unpoetical, unpretending, unpretentious, unreserved, unrestrained,
   unswerving, unswervingly, unvarnished, unveeringly, upright,
   upstanding, well-defined