antelope
羚 refers specifically to an antelope, a type of horned grazing animal. The meaning is narrow and does not extend to broader concepts.
羚 combines 羊 (sheep/goat) with 令, which likely provides the sound. The character was created to name the antelope, an animal resembling a goat or sheep.
The left side is a sheep 羊, and the right side 令 looks like a person giving a command. Picture a shepherd commanding a flock of antelope-like sheep.
For レイ, imagine a ray of sunlight hitting an antelope's horns: ray -> レイ, and the antelope stands proudly in the light.
serow; wild goat
Tibetan antelope (Pantholops hodgsonii); chiru
four-horned antelope (Tetracerus quadricornis); chousingha
Japanese serow (Capricornis crispus)
pronghorn (Antilocapra americana); prong buck; pronghorn antelope
gnu; wildebeest
antelope
gerenuk (Litocranius walleri); Waller's gazelle