by Edu, Rafa and Malcolm

 Ambivalence (noun)  - the simultaneous existence of conflicting feelings or thoughts.  From the Latin words “ambi” meaning “on both sides” and “valere” meaning “to be strong”

 Avail (noun)  -Use, benefit, or advantage  From the Latin words "ad” meaning “to” and valere meaning “ to be strong”

 Equivalent (adjective)  -Similar in function  From the Latin words “aequus” meaning “equal” and “valere”

 Evaluation (noun)  -The act of judgment the worth of something.  From the Latin word “ex” meaning “out” and valere

 Evince (trans. verb)  -To show or exhibit, as an emotion  From the Latin “ex”, an intensive prefix and “vincere” meaning “to conquer”

 Invalid (adjective)  -worthless  From the Latin “in”, and “valere” meaning “to be strong”

 Invaluable (adjective)  -Indispensable  From Latin “in” meaning not and value meaning “estimate value of”

 Prevail (intrans. verb)  -to be greater in strength or influence; triumph  From the Latin “prae” meaning “before” and valere

 Valedictory (adjective)  -bidding farewell  From the Latin words “vale” meaning “farewell” and “dicere” meaning “to say”

 Vanquish (trans. verb)  -to defeat in battle  From the Latin word “vincere” meaning “to conquer”