Meatus is the singular. The plural form - which can hardly be necessary - would be meatus ( pronounced with a long last syllable "may-ya-TOOCE") in Latin, or simply meatuses.
The plural of meatus is meatuses or meatus - both forms are accepted.
The singular form of the demonstrative pronoun 'these' is this.
A meatus is a tubular opening or passage in the body.
The singular form of "cuffs" is cuff.
No, external auditory meatus and external acoustic meatus refer to the same structure, which is the ear canal that leads from the outer ear to the eardrum.
The singular form of "stratum" is "stratum." The word does not change in its singular form.
The singular form of feet is foot.
The singular form of diagnoses is diagnosis.
The singular form of scissors is "scissor."
The singular form of "oases" is "oasis."
The singular form of "dice" is "die."
The singular form of "wash" is "washing."