Spiritless is a related term of nonchalant.

As adjectives the difference between spiritless and nonchalant

is that spiritless is lacking energy, drive, motivation or emotion enervated while nonchalant is casually calm and relaxed.

As nouns the difference between playmate and mistress

is that playmate is a companion for someone (especially a child) to play with while mistress is a woman, specifically one with great control, authority or ownership.

As a noun ingredient

is one of the substances present in a mixture.

As an adjective elementary is

relating to the basic, essential or fundamental part of something.

Stamp is a related term of rank.

As a noun stamp

is an act of stamping the foot, paw or hoof.

As a verb stamp

is to step quickly and heavily, once or repeatedly.

As an adjective rank is

heavy, serious, grievous.

Marked is a synonym of special.

As adjectives the difference between marked and special

is that marked is while special is special.

Thrust is a related term of aggression.

As nouns the difference between thrust and aggression

is that thrust is (fencing) an attack made by moving the sword parallel to its length and landing with the point while aggression is aggression.

As a verb thrust

is (lb) to make advance with.

Problematical is a related term of puzzling.

As adjectives the difference between problematical and puzzling

is that problematical is doubtful or disputed while puzzling is difficult to understand or explain; enigmatic or confusing; perplexing.

As a verb puzzling is

.

As a noun puzzling is

time spent pondering something confusing.

Pertinence is a related term of association.

As nouns the difference between pertinence and association

is that pertinence is the quality of being pertinent while association is the act of associating.

Weakened is a related term of ill.

As adjectives the difference between weakened and ill

is that weakened is reduced, made less strong while ill is (label) evil; wicked (of people).

As a verb weakened

is (weaken).

As an adverb ill is

not well; imperfectly, badly; hardly.

As a noun ill is

(often pluralized) trouble; distress; misfortune; adversity.

Lightfooted is a related term of graceful.

As adjectives the difference between lightfooted and graceful

is that lightfooted is while graceful is having or showing grace in movement, shape, or proportion.