pipio

• (Classical Latin) IPA^(key): /ˈpiː.pi.oː/, [ˈpiːpioː]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈpi.pi.o/, [ˈpiːpio]

From pīpiō (“chirp”, verb; see etymology 2) +‎ -ō (noun-forming suffix).

pīpiō m (genitive pīpiōnis); third declension

1. chirping bird
2. squab

Third-declension noun.

Case	Singular	Plural
Nominative	pīpiō	pīpiōnēs
Genitive	pīpiōnis	pīpiōnum
Dative	pīpiōnī	pīpiōnibus
Accusative	pīpiōnem	pīpiōnēs
Ablative	pīpiōne	pīpiōnibus
Vocative	pīpiō	pīpiōnēs

• Walther von Wartburg (1928–2002) “pīpio”, in Französisches Etymologisches Wörterbuch, volumes 8: Patavia–Pix, page 556

Of imitative origin.

pīpiō (present infinitive pīpiāre); first conjugation, no passive, no perfect or supine stem

1. to pipe or chirp

Conjugation of pīpiō (first conjugation, no supine stem, no perfect stem, active only)
indicative		singular			plural
		first	second	third	first	second	third
active	present	pīpiō	pīpiās	pīpiat	pīpiāmus	pīpiātis	pīpiant
	imperfect	pīpiābam	pīpiābās	pīpiābat	pīpiābāmus	pīpiābātis	pīpiābant
	future	pīpiābō	pīpiābis	pīpiābit	pīpiābimus	pīpiābitis	pīpiābunt
subjunctive		singular			plural
		first	second	third	first	second	third
active	present	pīpiem	pīpiēs	pīpiet	pīpiēmus	pīpiētis	pīpient
	imperfect	pīpiārem	pīpiārēs	pīpiāret	pīpiārēmus	pīpiārētis	pīpiārent
imperative		singular			plural
		first	second	third	first	second	third
active	present	—	pīpiā	—	—	pīpiāte	—
	future	—	pīpiātō	pīpiātō	—	pīpiātōte	pīpiantō
non-finite forms		active			passive
		present	perfect	future	present	perfect	future
infinitives		pīpiāre	—	—	—	—	—
participles		pīpiāns	—	—	—	—	—
verbal nouns		gerund				supine
		genitive	dative	accusative	ablative	accusative	ablative
		pīpiandī	pīpiandō	pīpiandum	pīpiandō	—	—

From the previous verb.

pīpiō (present infinitive pīpiāre, perfect active pīpiāvī, supine pīpiātum); first conjugation

1. to whimper
2. (transitive) to pour out (whimpers)

Conjugation of pīpiō (first conjugation)
indicative		singular			plural
		first	second	third	first	second	third
active	present	pīpiō	pīpiās	pīpiat	pīpiāmus	pīpiātis	pīpiant
	imperfect	pīpiābam	pīpiābās	pīpiābat	pīpiābāmus	pīpiābātis	pīpiābant
	future	pīpiābō	pīpiābis	pīpiābit	pīpiābimus	pīpiābitis	pīpiābunt
	perfect	pīpiāvī	pīpiāvistī	pīpiāvit	pīpiāvimus	pīpiāvistis	pīpiāvērunt, pīpiāvēre
	pluperfect	pīpiāveram	pīpiāverās	pīpiāverat	pīpiāverāmus	pīpiāverātis	pīpiāverant
	future perfect	pīpiāverō	pīpiāveris	pīpiāverit	pīpiāverimus	pīpiāveritis	pīpiāverint
passive	present	pīpior	pīpiāris, pīpiāre	pīpiātur	pīpiāmur	pīpiāminī	pīpiantur
	imperfect	pīpiābar	pīpiābāris, pīpiābāre	pīpiābātur	pīpiābāmur	pīpiābāminī	pīpiābantur
	future	pīpiābor	pīpiāberis, pīpiābere	pīpiābitur	pīpiābimur	pīpiābiminī	pīpiābuntur
	perfect	pīpiātus + present active indicative of sum
	pluperfect	pīpiātus + imperfect active indicative of sum
	future perfect	pīpiātus + future active indicative of sum
subjunctive		singular			plural
		first	second	third	first	second	third
active	present	pīpiem	pīpiēs	pīpiet	pīpiēmus	pīpiētis	pīpient
	imperfect	pīpiārem	pīpiārēs	pīpiāret	pīpiārēmus	pīpiārētis	pīpiārent
	perfect	pīpiāverim	pīpiāverīs	pīpiāverit	pīpiāverīmus	pīpiāverītis	pīpiāverint
	pluperfect	pīpiāvissem	pīpiāvissēs	pīpiāvisset	pīpiāvissēmus	pīpiāvissētis	pīpiāvissent
passive	present	pīpier	pīpiēris, pīpiēre	pīpiētur	pīpiēmur	pīpiēminī	pīpientur
	imperfect	pīpiārer	pīpiārēris, pīpiārēre	pīpiārētur	pīpiārēmur	pīpiārēminī	pīpiārentur
	perfect	pīpiātus + present active subjunctive of sum
	pluperfect	pīpiātus + imperfect active subjunctive of sum
imperative		singular			plural
		first	second	third	first	second	third
active	present	—	pīpiā	—	—	pīpiāte	—
	future	—	pīpiātō	pīpiātō	—	pīpiātōte	pīpiantō
passive	present	—	pīpiāre	—	—	pīpiāminī	—
	future	—	pīpiātor	pīpiātor	—	—	pīpiantor
non-finite forms		active			passive
		present	perfect	future	present	perfect	future
infinitives		pīpiāre	pīpiāvisse	pīpiātūrum esse	pīpiārī	pīpiātum esse	pīpiātum īrī
participles		pīpiāns	—	pīpiātūrus	—	pīpiātus	pīpiandus
verbal nouns		gerund				supine
		genitive	dative	accusative	ablative	accusative	ablative
		pīpiandī	pīpiandō	pīpiandum	pīpiandō	pīpiātum	pīpiātū

• “pipio”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• pipio in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.