Who knows what a guru is?

  Grief \Grief\ (gr[=e]f), n. [OE. grief, gref, OF. grief, gref,
     F. grief, L. gravis heavy; akin to Gr. bary`s, Skr. guru,
     Goth. ka['u]rus. Cf. {Barometer}, {Grave}, a., {Grieve},
     {Gooroo.}]
     1. Pain of mind on account of something in the past; mental
        suffering arising from any cause, as misfortune, loss of
        friends, misconduct of one's self or others, etc.; sorrow;
        sadness.
  
              The mother was so afflicted at the loss of a fine
              boy, . . . that she died for grief of it. --Addison.
  
     2. Cause of sorrow or pain; that which afficts or distresses;
        trial; grievance.
  
              Be factious for redress of all these griefs. --Shak.
  
     3. Physical pain, or a cause of it; malady. [R.]
  
              This grief (cancerous ulcers) hastened the end of
              that famous mathematician, Mr. Harriot. --Wood.
  
     {To come to grief}, to meet with calamity, accident, defeat,
        ruin, etc., causing grief; to turn out badly. [Colloq.]
  
     Syn: Affiction; sorrow; distress; sadness; trial; grievance.
  
     Usage: {Grief}, {Sorrow}, {Sadness}. Sorrow is the generic
            term; grief is sorrow for some definite cause -- one
            which commenced, at least, in the past; sadness is
            applied to a permanent mood of the mind. Sorrow is
            transient in many cases; but the grief of a mother for
            the loss of a favorite child too often turns into
            habitual sadness. ``Grief is sometimes considered as
            synonymous with sorrow; and in this case we speak of
            the transports of grief. At other times it expresses
            more silent, deep, and painful affections, such as are
            inspired by domestic calamities, particularly by the
            loss of friends and relatives, or by the distress,
            either of body or mind, experienced by those whom we
            love and value.'' --Cogan. See {Affliction}.