Atoms of the same element that have different masses are called isotopes. Different masses result when there are different numbers of neutrons. All atoms of a particular element have the same number...
Definition of absent. 1 : not present at a usual or expected place : missing was absent from class today sharing memories of absent friends She was conspicously absent [=her absence was very noticeable] at the meeting. absently. adverb He replied absently to her question. Examples of absent in a sentence.
Webster Dictionary(0.00 / 0 votes)Rate this definition: 1  Absent(adj) being away from a place; withdrawn from a place; not present. 2  Absent(adj) not existing; lacking; as, the part was rudimental or absent. 3  Absent(adj) inattentive to what is passing; absent-minded; preoccupied; as, an absent air.