1. devices used to make hair straight by applying heat
Usage: plural form of straightener
2. tools or devices used to make something straight or aligned
Usage: general use; plural form of straightener

Examples

• She uses ceramic straighteners to smooth her curly hair.
• The hair straighteners take five minutes to heat up.
• Professional straighteners work better than cheap ones.
• Don't forget to unplug the straighteners after use.
• The carpenter used metal straighteners to align the boards.
• These straighteners can damage your hair if used too often.