admarginate is a learned coinage from Latin ad- ('to') + margo (genitive marginis, 'edge, margin') + -ate, meaning to write at the margin. Morphologically, the word is transparent: -ate is attached to the older base named in the history, so the modern form packages an inherited or borrowed stem inside a later English derivative. In modern use, the verb sense is "to write notes in the margin of a text", which keeps the etymology connected to the word's present dictionary value rather than treating it as a merely historical label. The wider word family includes related English forms such as margin, marginal, marginalia, showing how the same base continues to support neighboring English vocabulary. The principal historical forms in the chain include Latin margo, which anchor the explanation in named linguistic material.