Synonyms of transparent in English:

see-through, clear, translucent, pellucid, crystal clear, crystalline, limpid, glassy, glass-like, liquid

unclouded, uncloudy

rare transpicuous

filmy, gauzy, fine, sheer, light, lightweight, thin, flimsy, see-through, diaphanous, chiffony, gossamer, delicate

obvious, explicit, unambiguous, unequivocal, clear, lucid, straightforward, plain, plain as the nose on your face, as plain as the nose on your face, apparent, unmistakable, manifest, conspicuous, patent, indisputable, self-evident

rare transpicuous

blatant, flagrant, obvious, patent, manifest, undisguised, unconcealed, barefaced, glaring, shameless, brazen, bold, unmistakable, clear, plain, visible, noticeable, recognizable, distinct, evident, apparent, perceptible, discernible, palpable

archaic arrant

frank, open, candid, honest, direct, forthright, unreserved, plain-spoken, straight, straightforward, ingenuous, innocent, guileless, simple, artless

accountable

informal upfront