Having a collar (or other encircling demarcation).(adjective)
Simple past tense and past participle of collar.(verb)
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Use "collared" in a sentence
"Gilbert Arenas watched in collared shirt and tie on the bench."
"Other ways that utilities hedge are through fixed-price contracts and through so-called "collared" price contracts -- which set floor and ceiling prices."
"The investor is said to have "collared" the shares, limiting potential gains as well as potential losses."