备 (bèi) as a verb is a bound form meaning 'to prepare, to equip' — it often appears in compounds (e.g., 准备, 装备) and is more general than specific siblings like 筹备 (arrange an event) or 配备 (allocate equipment). The adverb sense 'fully; completely' is literary, used in formal expressions (e.g., 备受 'suffer fully', 备至 'to the utmost'), and contrasts with everyday words like 满 (full) or 全力 (with all one's effort).