'To beat the rap' definitions:

Definition of 'To beat the rap'

From: GCIDE

Beat \Beat\, v. i.
1. To strike repeatedly; to inflict repeated blows; to knock vigorously or loudly. [1913 Webster]
The men of the city . . . beat at the door. --Judges. xix. 22. [1913 Webster]
2. To move with pulsation or throbbing. [1913 Webster]
A thousand hearts beat happily. --Byron. [1913 Webster]
3. To come or act with violence; to dash or fall with force; to strike anything, as rain, wind, and waves do. [1913 Webster]
Sees rolling tempests vainly beat below. --Dryden. [1913 Webster]
They [winds] beat at the crazy casement. --Longfellow. [1913 Webster]
The sun beat upon the head of Jonah, that he fainted, and wished in himself to die. --Jonah iv. 8. [1913 Webster]
Public envy seemeth to beat chiefly upon ministers. --Bacon. [1913 Webster]
4. To be in agitation or doubt. [Poetic] [1913 Webster]
To still my beating mind. --Shak. [1913 Webster]
5. (Naut.) To make progress against the wind, by sailing in a zigzag line or traverse. [1913 Webster]
6. To make a sound when struck; as, the drums beat. [1913 Webster]
7. (Mil.) To make a succession of strokes on a drum; as, the drummers beat to call soldiers to their quarters. [1913 Webster]
8. (Acoustics & Mus.) To sound with more or less rapid alternations of greater and less intensity, so as to produce a pulsating effect; -- said of instruments, tones, or vibrations, not perfectly in unison. [1913 Webster]
A beating wind (Naut.), a wind which necessitates tacking in order to make progress.
To beat about, to try to find; to search by various means or ways. --Addison.
To beat about the bush, to approach a subject circuitously.
To beat up and down (Hunting), to run first one way and then another; -- said of a stag.
To beat up for recruits, to go diligently about in order to get helpers or participators in an enterprise.
To beat the rap, to be acquitted of an accusation; -- especially, by some sly or deceptive means, rather than to be proven innocent. [1913 Webster]