(i.) Any words that are quite new to you. Look them out in the dictionary, and notice their derivation and use; if you do not do this you will find the same word new to you the next time you meet with it.
(ii.) English Derivatives.—As you have seen, these will often help you to the root-meaning of a word. Thus:—
reiectis = reject, throw away
insilirent = insult, jump on
and in the case of verbs, as these two examples show, derivatives are most easily found from the supine stem.
N.B.—This must be done very carefully, because many such English derivatives have come from Latin words after they had wholly, or in part, lost their classical meaning, or from Latin words not found at all in classical Latin.
A great many other English words are derived from the Latin of this passage—e.g. pugnacious, (with) celerity, fact, except, military, manual, super-sede, vulnerable, hostile, sinister, uni-corn, and many others.
(iii.) Prefixes.—Notice especially the force of prepositions and inseparable particles in composition, e.g.:—
re- in re-iectis, re-vellerent, restitutum.
in- in impetus, insilirent.