One word substitute is Deponent.

Deponent: a person who makes a deposition or affidavit under oath.
Appellant: a person who applies to a higher court for a reversal of decision of a lower court.
Witness: a person who sees an event, typically a crime or accident, take place.
Litigant: a person involved in a lawsuit.

One word substitution is Pseudonym.

Nickname: a familiar or humorous name given to a person or thing instead of or as well as real name.
Pseudonym: a fictitious name, especially one used by an author.
Nomenclature: devising or choosing of names for things, especially in a science or or discipline.
Title: a name that describes someone's position or job.

One word substitute is Pedantic.

Pedantic: excessively concerned with minor details or rules; overscrupulous.
Ornate: elaborately or highly decorated.
Verbose: using or expressed in more words than are needed.
Pompous: affectedly grand, solemn, or self-important.

One word substitute is Portable.

Handy: convenient to handle or use; useful.
Portable: able to be easily carried or moved, especially because being of a lighter and smaller version than usual.
Potable: safe to drink; drinkable.
Bearable: able to be endured.

One word substitute is Omniscient.

Learned: (of a person) having acquired much knowledge through study.
Omnipresent: widely or constantly encountered; widespread.
Omnipotent: (of a deity) having unlimited power.
Omniscient: knowing everything.

One word substitute is Invulnerable.

Invulnerable: impossible to harm or damage.
Invincible: too powerful to be defeated or overcome.
Infallible: incapable of making mistakes or being wrong.
Impregnable: (of a fortified position) unable to be captured or broken into.

One word substitute is Stoicism.

Docility: easily managed or handled.
Stoicism: endurance of pain or hardship without display of feelings and without complaint.
Patience: capacity to accept or tolerate delay, problems, or suffering without becoming annoyed or anxious.
Reticence: quality of being reticent; reserve.

One word substitute is Palatable.

Appetising: stimulating one's appetite.
Palatable: (of food or drink) pleasant to taste.
Tantalising: excite senses or desires of (someone).
Sumptuous: splendid and expensive-looking.

One word substitute is Smuggler.

Exporter: a person, country, or company that sends goods or services to anor country for sale.
Importer: a person or organization that brings goods or services into a country from abroad for sale.
Smuggler: a person who smuggles goods.
Imposter: a person who pretends to be someone else in order to deceive ors, especially for fraudulent gain.

One word substitute is Eloquence.

Discourse: written or spoken communication or debate.
Expression: action of making known one's thoughts or feelings.
Eloquence: fluent or persuasive speaking or writing.
Lecture: an educational talk to an audience, especially one of students in a university.