Undesigning

(a.) Having no artful, ulterior, or fraudulent purpose; sincere; artless; simple.

Thesaurus Entries

arcadian, bucolic, genuine, guileless, homespun, honest, inartificial, native, natural, naturelike, pastoral, real, rural, sincere, TRUE, unadorned, unaffected, unartificial, unassumed, unassuming, unbeguileful, unbeguiling, uncalculating, undeceitful, undeceiving, undeceptive, undisguised, undisguising, undissembled, undissembling, undissimulated, undissimulating, unembellished, unfeigned, unfeigning, unflattering, unpretended, unpretending, unpretentious, unspoiled, untrimmed, unvarnished