A planned reduction in training volume before a competition or a test, holding intensity high, so fatigue clears while fitness stays.
A taper is not a deload. A deload cuts both load and volume to recover mid-block; a taper cuts volume hard while keeping the weights heavy, because the heavy work is what keeps the skill and the strength.
The evidence points to cutting volume by 40 to 60 percent over 8 to 14 days while keeping intensity at or above 85 percent and keeping frequency the same. In practice: a lifter doing 16 heavy squat sets a week drops to 7, still at 85 to 90 percent, still squatting three times a week, with the last heavy single 5 to 7 days out.
The mistake is tapering too long. Two weeks off heavy work leaves most lifters flat rather than fresh, and detraining starts around the third week.