2 syllables:
cyrus, dyrus, gyrus, hiris, iris, irous, jairus, pyrus, tiris, tyrus, virus, xyris, beerus, birrus, cheer us, cirrus, cuirass, freerice, hear us, iiris, kriorus, lyris, miris, mirus, near us, pthirus, pyrrhus, seeress, sirus, viris

3 syllables:
bucyrus, delthyris, desirous, dutch iris, dwarf iris, inspire us, lathyrus, osiris, papyrus, plant virus, poxvirus, provirus, psithyrus, slow virus, subvirus, anguirus, aviris, epirus, jabirus, lampyris, magirus, osyris, pamiris, sotiris, tapirus, thamyris, tomyris, veneris

4 syllables:
alphavirus, anti-virus, antivirus, aphthovirus, arborvirus, arbovirus, astrovirus, bearded iris, bulbous iris, bunyavirus, circovirus, coltivirus, echovirus, english iris, filovirus, flavivirus, genus iris, german iris, hantavirus, herpesvirus, herpes virus, inovirus, kuttervirus, lentivirus, lyssavirus, megavirus, mimivirus, mycovirus, myxovirus, nairovirus, norovirus, oncovirus, parvovirus, persian iris, pestivirus, phlebovirus, pithovirus, pneumovirus, potyvirus, ranavirus, reovirus, retrovirus, rhabdovirus, rhinovirus, ribovirus, rotavirus, rubivirus, sapovirus, sequivirus, simplexvirus, smallpox virus, spanish iris, stinking iris, togavirus, torovirus, tumor virus, ultravirus, undesirous, vernal iris, yellow iris, zika virus, menticirrhus, panegyris, perochirus, polycirrus, strato-cirrus

5 syllables:
adenovirus, alfamovirus, animal virus, archaeothyris, arenavirus, arterivirus, baculovirus, billy ray cyrus, calicivirus, coronavirus, coxsackievirus, dalmatian iris, dependovirus, ebolavirus, ebola virus, enterovirus, erythrovirus, florentine iris, granulovirus, henipavirus, hepadnavirus, hepatovirus, japanese iris, luteovirus, morbillivirus, oncornavirus, orthopoxvirus, pandoravirus, papovavirus, picornavirus, poliovirus, rhadinovirus, sarbecovirus, suipoxvirus, tobamovirus, wound tumor virus

6 syllables:
aquabirnavirus, avast antivirus, herpes simplex virus, herpes zoster virus, influenzavirus, leporipoxvirus, lymphocryptovirus, mastadenovirus, metapneumovirus, orthohantavirus, orthomyxovirus, orthopneumovirus, papillomavirus, paramyxovirus, polyomavirus, varicellovirus, vesiculovirus

7 syllables:
alphacoronavirus, aviadenovirus, betacoronavirus, cytomegalovirus, deltacoronavirus, dionysus-osiris, gammacoronavirus, hepatitis a virus, orthohepadnavirus

8 syllables:
human papilloma virus, tobacco mosaic virus

9 syllables:
nucleopolyhedrovirus

11 syllables:
human immunodeficiency virus

2 syllables:
spirits, doris, morris, maurice, naris, harris, derris, merits, paris, orris, norris, boris, burris, chloris, ferris, gerris, myrrhis, ptloris

3 syllables:
slow loris, herb paris, clitoris, liquorice, phalaris, prioress, psephurus, trachurus

4 syllables:
acanthurus, chrysochloris, elaphurus, genus chloris, genus loris, genus paris, hypochaeris, pomaderris, slender loris, tetraneuris

5 syllables:
plaster of paris, agriocharis

6 syllables:
chamaecyparis