easily broken or cracked
liable not to survive setbacks or upsets; fragile
A brittle glory shineth in that face; as brittle as the glory is the face — Shakespeare
light and thin in tone; sharp
a brittle sound
lacking warmth or depth of feeling
brittle gaiety
brittlely /ʹbritl·li/ adv
brittleness noun
brittly adv
[Middle English britil, of Germanic origin]