The technical name for using someone else's words without giving adequate credit.
Using someone else's idea without acknowledging the source.
Paraphrasing someone else's argument as your own.
Presenting someone else's line of thinking in the development of an idea as if it were you own.
Presenting an entire paper or a major part of it developed exactly as someone else's line of thinking.
Arranging your idea exactly as someone else did - even though you acknowledge the source(s)s in parentheses.