| Subject | English | French |
| industr., construct. | anti-slip carpet underlay | dessous non-glissant pour tapis |
| industr., construct. | bonded underlay | thibaude à base de produits de synthèse |
| tech., industr., construct. | combined underlay | thibaude incorporée |
| health. | genes that underlie the dopamine system | gènes qui déterminent le système dopaminergique |
| transp., construct. | levelling underlay | couche de nivellement |
| nat.res. | loam, deeply underlain by clay | limon profondement supporté d'argile |
| nat.res. | loam, deeply underlain by clay | limon argileux sableux profondement supporté d'argile |
| nat.res. | loess, deeply underlain by clay | loess, profondement supporté d'argile |
| nat.res. | loess, deeply underlain by loam | loess, profondement supporté de limon argileux sableux |
| commun. | overlay/underlay | recouvrement - recouvert |
| nat.res. | peat, deeply underlain by sand | tourbe à couchis profond de sable |
| nat.res. | peat, underlain very deeply by gyttja | tourbe à couchis profond de gyttja |
| nat.res. | peat, underlain very deeply by mud | tourbe à couchis profond de gyttja |
| nat.res. | peat, underlain very deeply by sand | tourbe à couchis profond de sable |
| transp., construct. | plastic sheeting underlay | voile impermeable |
| transp., construct. | plastic sheeting underlay | feuille d'etancheite |
| transp., construct. | plastic sheeting underlay | membrane impermeable |
| transp., construct. | plastic sheeting underlay | film impermeable |
| industr. | plastic sheeting underlay | feuille d'isolation |
| construct. | plastic underlay | voile synthetique |
| construct. | plastic underlay | membrane synthetique |
| transp., construct. | plastic underlay | voile impermeable |
| construct. | plastic underlay | film synthetique |
| construct. | roof underlay | sous-toiture |
| construct. | roof underlay | s/toiture |
| tech., industr., construct. | separate underlay | thibaude libre |
| industr., construct. | toe-cap underlay | doublure de bout fleuri |
| nat.res. | underlain by... | supporté de... |
| industr., construct. | underlay paper | papier de protection |