from
The Collaborative International Dictionary of English v.0.48
Retinaculum \Ret`i*nac"u*lum\, n.; pl. {Retinacula}. [L., a
holdfast, a band. See {Retain}.]
1. (Anat.)
(a) A connecting band; a fraenum; as, the retinacula of
the ileocaecal and ileocolic valves.
(b) One of the annular ligaments which hold the tendons
close to the bones at the larger joints, as at the
wrist and ankle.
[1913 Webster]
2. (Zool.) One of the retractor muscles of the proboscis of
certain worms.
[1913 Webster]
3. (Bot.) A small gland or process to which bodies are
attached; as, the glandular retinacula to which the
pollinia of orchids are attached, or the hooks which
support the seeds in many acanthaceous plants.
[1913 Webster]