A person who augments or increases something; one who performs augmentation.
From augmentation (the act of augmenting) plus the agent suffix '-er' (one who does). This creates a noun describing a person defined by their role in increasing or enhancing.
This is a wonderfully old-fashioned word—while we'd say 'augmentor' today, calling someone an 'augmentationer' sounds like they're a formal professional dedicated to expansion!
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