.definition {
  display: inline;
  position: relative;
  border-bottom: 1px solid red;
  cursor: help;
}

.definition:hover {
  text-decoration: none;
}

.definition .definition_tooltip {
  background: #fff;
  background: -moz-linear-gradient(top, rgba(255,255,255,1) 0%, rgba(237,237,237,1) 100%); /* FF3.6+ */
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(255,255,255,1)), color-stop(100%,rgba(237,237,237,1))); /* Chrome,Safari4+ */
  background: -webkit-linear-gradient(top, rgba(255,255,255,1) 0%,rgba(237,237,237,1) 100%); /* Chrome10+,Safari5.1+ */
  background: -o-linear-gradient(top, rgba(255,255,255,1) 0%,rgba(237,237,237,1) 100%); /* Opera 11.10+ */
  background: -ms-linear-gradient(top, rgba(255,255,255,1) 0%,rgba(237,237,237,1) 100%); /* IE10+ */
  background: linear-gradient(to bottom, rgba(255,255,255,1) 0%,rgba(237,237,237,1) 100%); /* W3C */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f2ffffff', endColorstr='#f2ededed',GradientType=0 ); /* IE6-9 */

  -webkit-box-shadow: -2px 2px 0px 0px rgba(50, 50, 50, 0.75);
  -moz-box-shadow:    -2px 2px 0px 0px rgba(50, 50, 50, 0.75);
  box-shadow:         -2px 2px 0px 0px rgba(50, 50, 50, 0.75);

  border-radius: .5em;
  bottom: 100%;
  margin-bottom: 10px;
  color: $agile-blue;
  font-size: 16px;
  font-style: italic;
  display: none;
  left: 50%;
  margin-left: -135px;
  padding: 20px;
  width: 270px;
  position: absolute;
  z-index: 98;
}

.definition .definition_tooltip:before {
  border: solid;
  border-color: #ededed transparent;
  border-color: rgba(237,237,237,1) transparent;
  border-width: 10px 20px 0 20px;
  top: 100%;
  content: "";
  display: block;
  left: 50%;
  margin-left: -20px;
  position: absolute;
  z-index: 99;
}
.definition .definition_tooltip:after {
  border: solid;
  border-color: #ededed transparent;
  border-color: rgba(50,50,50,1) transparent;
  border-width: 11px 22px 0 22px;
  top: 100%;
  content: "";
  display: block;
  left: 50%;
  margin-left: -24px;
  position: absolute;
}

.definition:hover .definition_tooltip {
  display: block;
}