excuse vs should

excuse

verb
  • To provide an excuse for; to explain, with the aim of alleviating guilt or negative judgement. 

  • To forgive; to pardon. 

  • To relieve of an imputation by apology or defense; to make apology for as not seriously evil; to ask pardon or indulgence for. 

  • To allow to leave, or release from any obligation. 

noun
  • Explanation designed to avoid or alleviate guilt or negative judgment; a plea offered in extenuation of a fault. 

  • A defense to a criminal or civil charge wherein the accused party admits to doing acts for which legal consequences would normally be appropriate, but asserts that special circumstances relieve that party of culpability for having done those acts. 

  • An example of something that is substandard or of inferior quality. 

should

verb
  • To make a statement of what ought to be true, as opposed to reality. 

  • Will be likely to (become or do something); indicates a degree of possibility or probability that the stated thing will happen or be true in the future. 

  • Indicates that something is expected to have happened or to be the case now. 

  • Used to express a conditional outcome. 

  • With verbs such as 'see' or 'hear', usually in the second person, used to point out something remarkable in either a good or bad way. 

  • Used to impart a tentative, conjectural or polite nuance. 

  • Used to express what the speaker would do in another person's situation, as a means of giving a suggestion or recommendation. 

  • Simple past tense of shall. 

  • In questions, asks what is correct, proper, desirable, etc. 

  • Used to issue an instruction (traditionally seen as carrying less force of authority than alternatives such as 'shall' or 'must'). 

  • Used to give advice or opinion that an action is, or would have been, beneficial or desirable. 

  • Used to form a variant of the present subjunctive, expressing a state or action that is hypothetical, potential, mandated, etc. 

noun
  • Something that ought to be the case as opposed to already being the case. 

How often have the words excuse and should occurred in a corpus of books? (source: Google Ngram Viewer )