The phrase "a second arm" is correct and usable in written English.
It can be used in contexts where you are referring to an additional arm, either literally (as in anatomy or robotics) or metaphorically (as in support or assistance).
Example: "The new robot design features a second arm to enhance its functionality and efficiency in tasks."
Alternatives: "an additional arm" or "a supplementary arm".
It is seen almost as a second arm of government.
A second arm reliquary, this one for an unspecified saint, is startlingly naturalistic.
In one arm of the study, the early withdrawal penalty was 10percentt; in a second arm it was 20percentt; and in the third arm of the study no withdrawals were allowed before the early withdrawal date.
Our findings suggest a bifurcation of Smo activity in Hh response, with a Dlg5-independent arm for suppression of Gli repressor formation and a second arm involving Smo interaction with Dlg5 for Gli activation.
A second arm of the fiber bundle was guided to a Coherent powermeter EM-USB-J-25MB-LE (Coherent Inc., Santa Clara, California) to monitor the energy per pulse, which was used to normalize the acquired signals.
A second arm of response involves a gradual reengineering of health care delivery at the practice level, including the dissemination of patient-centered medical homes, the use of team-based approaches to care, and the expansion of care management beyond the practice to reach deep into the community.
A) Third arm B) Edible fingernails C) 180 degree neck rotation D) Elimination of mucous membranes.
And it also has the potential to begin a second arms race in director compensation, something probably best avoided.
The report warns that the continued push for a new generation of nuclear weapons could lead to a second arms race.
A third arm of research focuses on making computers smarter.
The South American spider monkey, considered a semibrachiator, uses its prehensile tail as a third arm.
