third-person singular of fit

• is the right size or shape for
• is suitable or appropriate for
• goes into the available space
• matches or agrees with
• equips or supplies with required parts

plural of fit meaning degree of suitability or match

• qualities of alignment, conformity, or tolerance between parts or data

plural of fit meaning sudden attack, bout, or outburst

• episodes of illness, coughing, laughter, or anger

initialism Flexible Image Transport System, an astronomy data file format

• common filename extension .fits for images and tables