hard; solid; stiff; tight; strong; firm (not viscous or easily moved); safe
compression; condensing; shortening; compression (of data)
layer; stratum; class; stratum; sheaf; counter for stories (of a building)
upper stratum (classes, stories, storeys); upper layer; layer above
elementary level; beginner level
textbook; coursebook; schoolbook
model; dummy; model (profession); fashion model; model (of a vehicle, machine, etc.); version; model (e.g. mathematical)
typical; representative; archetypal; quintessential; stereotypical; model
gaseous planet; gas planet
solid (body); solid matter; solid-state
minus; subtraction; negative (number); deficit; loss; disadvantage; drawback
main; principal; main dish; main course; main part; principal part
brown; light brown; tawny
lightning; electric illumination; light from an electric source
to flutter (e.g. a flag); to wave; to reverberate (e.g. thunder); to resound
origin; source; beginning; starting point
chaos; confusion; disorder; chaotic; confused; uncertain
coworker; co-worker; colleague; associate
staff officer; military staff; adviser; counselor; counsellor
left wing; left wing (of a bird or aircraft); left wing (of an army, building, etc.); left flank; left field; left fielder
right wing; right wing (of a bird or aircraft); right wing (of an army, building, etc.); right flank; right field; right fielder; right wing (in soccer, rugby, etc.)
natural environment; (the) environment
three dimensions; 3D; 3-D; real world; IRL; in real life
to surround; to crowd around; to gather around; to encircle; to besiege
orderly; regular; systematic; well-organized; well-organised; trim
(not) particularly; (not) especially; (not) very; (not) much
grateful; thankful; welcome; appreciated; evoking gratitude
first day of the month; the first of the month
attendee; participant; person present
rude; outspoken; presumptuous; cheeky
to pat (e.g. a dog); to rub; to stroke; to fondle; to caress