Lassitude

From "lassitudinem" - faintness or weariness.

Sounds to me more like Lassie fainting.

Venerate

Comes from a discussion about whether or not the word comes from Venus: beauty love and desire. It does! I venerate the word Venerate!

Dire

I find trying to write my essay is a dire task.

Dire means dreadful, terrible or disastrous.

Etymology:
1560s, from L. dirus "fearful, awful, boding ill," of unknown origin; perhaps from Oscan and Umbrian and perhaps cognate with Gk. deinos, from PIE base *dwei-.

Recidivist

An habitual convict (i.e. a criminal who reoffends).
So encountered because it was used in Porridge S03E05 "A Test of Character"

Etymology
re: Latin prefix to repeat
cadere - to fall back

This then became in French recidiviste, which is where the English word came from.

Omphalos

I think it was this word in John Simpson's autobiography: "Strange Places, Questionable People". Its usual meaning is the navel - and refers to sacred conical stones at the centre of oracles. It can also be used to mean centre.

Procrastinate

I am the queen of procrastination!  If I have any work to do, you can be sure I will find at least 5 other things to do first even though they are nowhere near as important...

To procrastinate is to delay or put off til another day.

Etymology:

1540s, from L. procrastinationem "a putting off," noun of action from procrastinare "put off till tomorrow," from pro- "forward" (see pro-) + crastinus "belonging to tomorrow," from cras "tomorrow," of unknown origin.

Agglutinate

To firmly stick together to form a mass.

Encountered due to French coursework, where apparently "agglutinés" is a known, well-used word.

Etymology
ad-: Latin prefix "to"
glutinare: Latin "to glue"
-ate: Latin suffix which makes an adjective.

Quinquennial

Once every 5 years. Came across this delightful word whilst reading the hilarious, yet disturbingly accurate (at least according to Edward Behr) Scoop by Evelyn Waugh.

Etymology:
Latin quinque: five,
Latin anneial: yearly.

Opsimathy

I came across this word while looking in the dictionary for another word.  This is one of the reasons why I enjoy reading the dictionary, I get introduced to new words :-)

Opsimathy means the process of acquiring information late in life.

Etymology:
1650s, from Gk. opsimathia "learning late in life," from opse "late" (related to opiso "backward" + opisthen "behind") + manthanein "to learn."