This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. Plural form of perimeter.

"Stationed in Texas and throughout the trans-Mississippi region, soldiers attended to road building, exploring, enforcing federal laws, protecting settlers, patrolling international borders, garrisoning coastal fortifications, and guarding the perimeters of Indian reservations."

dosimeters    estimators