The adjective is "sundry" (Sun + dry).
nuclear is a form of energy, not an adjective. Several possible answers are oldclear, nufoggy and raelcun
An antonym is a word that has an opposite meaning to the original word. For example the antonym of "happy" is "sad", or the antonym of "cold" is hot. The word "augment" means to make larger, more prominent or increase. There are therefore several suitable antonyms including "decrease", "diminish" and "reduce".
The antonym for over speculation can be several. One is not to invest at all, meaning prudent investing. Another would be conservative investing. Low volume trading is also most descriptive.
The word lair has several synonyms, but no antonym for it exists.
Tied is an adjective, that has several meaning like: to be bound, to be lashed, to be subjugated, to be enslaved etc.
An antonym is a word with the opposite meaning, but in many cases, one word may have several similar meanings, and the opposites may be quite different. However, "submission" is a fairly straightforward term without many alternative meanings, and the antonym is equally straightforward. It is "domination".
Miles from the nearest highway or town. This term is often used by backpackers, meaning several days hiking distance from the nearest road.
Several is usually an adjective e.g., I have been to Paris several times.
Severe is an adjective.
Single
There are several synonyms or near-synonyms: ACCIDENT (noun)/ ACCIDENTAL (adjective)/ ACCIDENTALLY (adverb) UNINTENTIONAL (adjective) / UNINTENTIONALLY (adverb) INADVERTENT (adjective) / INADVERTENTLY (adverb) UNPREMEDITATED (adjective meaning unplanned, usually a legal term)
There are several definitions. One is the name of a band in the United States. Another is as an adjective meaning rash, not thought out, impulsive, blind to consequences.