- A modified muscular pouch behind the stomach in the digestive tract of birds, having a thick lining and often containing ingested grit that aids in the breakdown of seeds before digestion.
- A similar digestive organ found in certain invertebrates, such as the earthworm.
- The second stomach of a bird, not counting the crop or craw as the first; the bulbous or muscular stomach (ventriculus bulbosus), succeeding the proventriculus and succeeded by the duodenum; the gigerium.
- The proventriculus or first true stomach of insects, generally armed inside with horny teeth. See cut under <internalXref urlencoded="Blattid%C3%A6">Blattidæ</internalXref>.—
- The stomach of some mollusks, as <em>Bullidæ</em>, when muscular and hardened.—
- Figuratively, temper: now only in the phrase <em>to fret one's gizzard.</em>
- The second, or true, muscular stomach of birds, in which the food is crushed and ground, after being softened in the glandular stomach (crop), or lower part of the esophagus; the gigerium.
- A thick muscular stomach found in many invertebrate animals.
- A stomach armed with chitinous or shelly plates or teeth, as in certain insects and mollusks.
- an American herring (<spn>Dorosoma cepedianum</spn>) resembling the shad, but of little value.
- to harass; to vex one's self; to worry.
- to be difficult of digestion; to be offensive.
- A portion of the <xref>esophagus</xref> of either a bird or an <xref>annelid</xref> that contains ingested <xref>grit</xref> and is used to grind up ingested food before it is transferred to the <xref>stomach</xref>.
- thick-walled muscular pouch below the crop in many birds and reptiles for grinding food