-τρα

-τρα • (-tra) n

1. nominative plural of -τρον (-tron)
2. accusative plural of -τρον (-tron)
3. vocative plural of -τρον (-tron)

• IPA^(key): /tɾa/

From Byzantine Greek -τρια (-tria), with loss of middle ι.

-τρα • (-tra) f

1. added to a verb to create words denoting a female occupation:

   ‎πλένω (pléno, “to wash”) + ‎-τρα (-tra) → ‎πλύστρα (plýstra, “laundress, washer woman”)

   ‎ράβω (rávo, “to sew”) + ‎-τρα (-tra) → ‎ράφτρα (ráftra, “seamstress”)

   ‎κλέβω (klévo, “to steal”) + ‎-τρα (-tra) → ‎κλέφτρα (kléftra, “female thief”)

2. added to a noun or verb to create words denoting a female who has that quality or does that action:

   ‎πλανεύω (planévo, “to lead astray, to seduce”) + ‎-τρα (-tra) → ‎πλανεύτρα (planéftra, “seductress”)

   ‎φταίω (ftaío, “to be at fault”) + ‎-τρα (-tra) → ‎φταίχτρα (ftaíchtra, “woman to blame, woman at fault”)

3. added to a noun or verb to create words denoting an animal or an inanimate object or event that has that quality or does that action:

   ‎τσούζω (tsoúzo, “to sting”) + ‎-τρα (-tra) → ‎τσούχτρα (tsoúchtra, “jellyfish”)

   ‎ρουφώ (roufó, “to suck”) + ‎-τρα (-tra) → ‎ρουφήχτρα (roufíchtra, “whirlpool”)

   ‎χέζω (chézo, “to shit”) + ‎-τρα (-tra) → ‎χέστρα (chéstra, “shitter, toilet”)

The genitive plural is uncommon and considered awkward by scholars.

From Ancient Greek -τρα (-tra).

-τρα • (-tra) n pl

1. added to a noun or verb to create words denoting a fee, a cost or a monetary reward:

   ‎διδάσκω (didásko, “to teach”) + ‎-τρα (-tra) → ‎δίδακτρα (dídaktra, “tuition fees”)

   ‎εξέταση (exétasi, “examination”) + ‎-τρα (-tra) → ‎εξέταστρα (exétastra, “examination fees”)

   ‎ευρετής (evretís, “finder”) + ‎-τρα (-tra) → ‎εύρετρα (évretra, “finder's fee”)

The stress (not visible in this table) moves forward in the genitive, eg δίδακτρα - διδάκτρων.