Antonyms of adj rattlebrained

1 sense of rattlebrained

Sense 1
rattlebrained, rattlepated, scatterbrained, scatty -- (lacking sense or discretion; "his rattlebrained crackpot ideas"; "how rattlepated I am! I've forgotten what I came for"- Glenway Westcott)

INDIRECT (VIA foolish) -> wise -- (having or prompted by wisdom or discernment; "a wise leader"; "a wise and perceptive comment")

Similarity of adj rattlebrained

1 sense of rattlebrained

Sense 1
rattlebrained, rattlepated, scatterbrained, scatty -- (lacking sense or discretion; "his rattlebrained crackpot ideas"; "how rattlepated I am! I've forgotten what I came for"- Glenway Westcott)
       => foolish (vs. wise) -- (devoid of good sense or judgment; "foolish remarks"; "a foolish decision")