Plain English Meaning
Making something seem smaller or less important than it really is, so it feels easier to live with.
Full Definition
A defense mechanism in which a person reduces the apparent importance, severity, or seriousness of an event, mistake, or shortcoming in order to avoid the discomfort of fully acknowledging it. In aviation training, it appears when a learner downplays errors or weaknesses rather than confronting them honestly.
Context Anchor
Seen in aviation human factors and instructor discussions about denial, self-assessment, and student reactions to mistakes or risk.
Derivation
From the Latin 'minimus' meaning 'smallest.' Minimization is literally the act of making something appear as small as possible — in this case, shrinking the perceived size of a problem or mistake.