- alarum11
- ambulacrum25
- antiserum14
- antrum11
- arum8
- asarum10
- aurum10
- candelabrum24
- centrum15
- cerebrum18
- chetrum16
- claustrum18
- cockalorum25
- colostrum17
- conundrum20
- cuprum17
- decorum15
- diestrum13
- drum9
- durum11
- eardrum12
- electrum16
- elytrum14
- epidendrum20
- estrum10
- ferrum13
- forum12
- fulcrum19
- grum10
- humdrum18
- indecorum18
- involucrum24
- iterum10
- jorum18
- kettledrum20
- labarum15
- labrum14
- larum10
- lustrum13
- ngultrum17
- nostrum12
- oestrum11
- panjandrum29
- philtrum18
- pittosporum21
- plastrum16
- plectrum19
- pyrethrum20
- quorum20
- rostrum11
- rum7
- sacrum13
- scrum12
- sequestrum24
- serum9
- simulacrum22
- sistrum11
- spectrum18
- strum9
- tantrum12
- thrum11
- variorum16
- veratrum16