All 3 Uses of

inevitable
in
To the Lighthouse

but then, raising his hand, half-way to his face as if to avert, to brush off, in an agony of peevish shame, their normal gaze, as if he begged them to withhold for a moment what he knew to be inevitable, as if he impressed upon them his own child-like resentment of interruption, yet even in the moment of discovery was not to be routed utterly, but was determined to hold fast to something of this delicious emotion, this impure rhapsody of which he was ashamed, but in which he revelled—he turned abruptly, slammed his private door on them;†
Part 1

inevitable = certain to happen

And then, letting her eyes slide imperceptibly above the pool and rest on that wavering line of sea and sky, on the tree trunks which the smoke of steamers made waver on the horizon, she became with all that power sweeping savagely in and inevitably withdrawing, hypnotised, and the two senses of that vastness and this tininess (the pool had diminished again) flowering within it made her feel that she was bound hand and foot and unable to move by the intensity of feelings which reduced her own body, her own life, and the lives of all the people in the world, for ever, to nothingness.†
Part 1

inevitably = with certainty that it will happen

Definition:

certain to happen (even if one tried to prevent it)