i Register
In some senses, gustless is marked as obsolete. Watch for register when choosing this word.
adj
tasteless; insipid
[…] they might after give the expressed and less useful part of the cods and remaining pulp unto their swine: which, being no gustless or unsatisfying offal, might be well desired by the prodigal in his hunger.
Again, it is a base abject temper, speaks a mind sunk and lost in carnality, and that, having dethroned and abjured reason, hath abandoned itself to the hurry of vile appetite and sold its liberty and sovereignty for the insipid, gustless pleasures of sense.
adj
Without gusts (of wind).
Except in broken country, the sand cloud seems to glide steadily over the desert like a moving carpet, and the wind is comparatively gustless.
Unlike fixed-wing aircraft, the rotor experiences oscillatory aerodynamic effects even in steady, gustless forward flight.