Sadly I don't think we have the words for murder, six or secret. Kill is KRii, LO is deceive, TahRODiiS is treacherous, SMOLiiN is passion, NOK is lie. I think those fit for Mephala one way or another.
Some words that might fit other Daedra:
Azura: KReiN (sun), ViiNTaaS (shining)
Boethiah: very much like Mephala. LO, NOK, KRii.
Clavicus Vile: HIND (wish)
Hermaeus Mora: DahMaaN (remember), VahRUKT (memory), DEZ (Fate)
Hircine: Nir (hunt), SIVaaS (beast)
Jyggalag: UZNahGaaR (unbridled), YORiiK (march)
Malacath: VaaT (swear/swore), VahRiiN (sworn), MULaaG (strength), NahKRiiN (vengeance)
Mehrunes Dagon: ENVENaaR (extinguish), AL (destroyer), PaaR (ambition), SULeyK (power)
Meridia: LaaS (life), KReiN/SHUL (sun), ViiNTaaS (shining)
Molag Bal: THUR (overlord), FeyN (bane)
Namira: KRUZiiK (ancient), VULOM (darkness), DINOK (death), Zii (spirit)
Nocturnal: VULON (night), VUL (dark), VOKUN (shadow)
Peryite: KRASaaR (sickness), LiiV (wither), BeiN (foul)
Sanguine: SMOLiiN (passion)
Sheogorath: Can't find anything that relates to madness.
Vaermina: HahNU (dream), VULON (night)