Immernaut

noun
A crewperson aboard a vessel that breaches the meniscus of everyday space.
Origin
Derived from immersum (under the surface) and nautēs (sailor).
Source
Embassytown

Terranaut

noun
The intrepid breed of men that go down into the uncharted seas of time gas below Earth’s crust.
Origin
Derived from terra (ground) and nautēs (traveller).
Source
The Night That All Time Broke Out

Hilfer

noun informal
An ethnologist of high intelligence life forms.
Source
Rocannon’s World

Memcordist

noun
A person who makes recordings of their sensorium.
Origin
Portmanteau of ‘memory’ and ‘recordist’.
Source
Central Station

Loyaltician

noun
An advisor in matters of fealty.
Source
Surface Detail

Geotect

noun
A person who designs the topography of artificial land masses.
Origin
Formed from geo (Earth) and téktōn (builder).
Source
The Diamond Age

Ractor

noun
A professional performer of interactive fiction.
Origin
Abbreviation of ‘interactive (“ractive”) actor’.
Source
The Diamond Age

Synthespian

noun
A computer-generated artificial actor appearing in motion pictures.
Origin
Portmanteau of ‘synthetic’ and ‘thespian’.
Source
Idoru

Xenonaut

noun
  1. (plural proper) An international organisation defending Earth from extraterrestrial invasion.
  2. A member of the Xenonauts defence force.
Origin
Derived from ksenos (foreign) and nautēs (traveller).
Source
Xenonauts

Ghostbuster

noun
A professional paranormal investigator and exterminator.
Source
Ghostbusters

RoboCop

noun proper
A cyborg law enforcer, formerly Detroit Police Officer Alexander James Murphy.
Source
RoboCop

Xenotech

noun
A specialist in the analysis of alien technology.
Origin
Abbreviation of ‘xeno-technologist’.
Source
Gateway