Not closed

unclosed, accessible, clear, open to view, uncovered, disclosed, divulged, introduced, initiated, inaugurated, begun, full-blown, unfurled, susceptible, ajar, agape, gaping, yawning, wide, rent, torn, spacious, broad gauge, unshut, expansive, extensive, spread out, vistaed, revealed, unenclosed; see also senses 2, 4.

Antonyms tight*, closed*, shut. *

Not obstructed

unlocked, unbarred, unbolted, unlatched, unblocked, unfastened, cleared, removed, made passable, unsealed, unobstructed, unoccupied, vacated, unburdened, emptied; see also sense 1.

Antonyms taken*, barred*, blocked.

Not forbidden

free, unrestricted, permitted, allowable, free of access, public, welcoming, not posted; see also admissible, permitted.

Antonyms refused*, restricted*, forbidden. *

Not protected

unguarded, unsecluded, liable, exposed, out in the weather, uncovered, apart, fallen open, unshut, unroofed, insecure, unsafe, conspicuous, unhidden, unconcealed, subject, sensitive; see also sense 1, unsafe.

Antonyms safe*, secluded*, secure. *

Not decided

in question, up for discussion, debatable; see controversial, questionable 1, uncertain 2.

Not solid

airy, fretted, fretworked, openworked, intersticed, filigree; see also penetrable.

Antonyms firm*, solid*, impenetrable. *

Frank

plain, candid, straightforward; see frank.

Obvious

apparent, well-known, clear; see obvious 1. See syn. study at frank.

To begin

start, inaugurate, initiate; see begin 1, 2.

To move aside a prepared obstruction

unbar, unlock, unclose, clear, admit, turn back, reopen, open the lock, lift the latch, free, loosen, disengage, throw open, lay open, swing wide, unfasten, undo, unbolt, throw back the bolt, turn the key, turn the knob.

Antonyms close*, shut*, lock. *

To make an opening

force an entrance, breach, make an aperture, cut in, tear down, push in, shatter, destroy, burst in, break open, cave in, burst out from, penetrate, cleave, pierce, force one's way into, smash, prick, punch a hole into, slit, puncture, crack, muscle in*, jimmy*; see also force 2, remove 1.

Antonyms repair*, seal*, mend. *

To make available

make accessible, put on sale, put on view, open to the public, make public, put forward, free, make obtainable, make usable, prepare, present, make convenient, make ready.

Antonyms remove*, put away*, lock up. *

To begin business

open for business, hang out one's shingle, receive business, go into business, set up shop, get to work.

To expose to fuller view

unroll, unfold, uncover; see expose 1, reveal 1.