What's the difference between aurora and isochasm?

Aurora

Definition:

(n.) The rising light of the morning; the dawn of day; the redness of the sky just before the sun rises.
(n.) The rise, dawn, or beginning.
(n.) The Roman personification of the dawn of day; the goddess of the morning. The poets represented her a rising out of the ocean, in a chariot, with rosy fingers dropping gentle dew.
(n.) A species of crowfoot.
(n.) The aurora borealis or aurora australis (northern or southern lights).

Example Sentences:

(1) 139 cases of Mycoplasma pneumoniae infection (serological diagnosis) were treated at Aurora Hospital, Helsinki, between January 1975 and August 1977.
(2) Holmes, 25, is charged with more than 166 separate offences relating to the mass shooting of 20 July in Aurora, including first degree murder.
(3) These can lead to communications blackouts around the Earth and produce aurorae; indeed, there have been several nice displays over recent weeks.
(4) The passengers were then flown to an Australian icebreaker, the Aurora Australis, which had cracked through ice floes and was now sailing towards Australia's Casey research base.
(5) Clinton met with Jane Dougherty, sister of Mary Sherlach, who was slain at the Sandy Hook Elementary School shooting in Newtown, Connecticut, in 2012; Tom Sullivan and Matthew Jenks, the father and brother-in-law, respectively, of Alex Sullivan, who was killed in the 2012 movie theater shootings in Aurora, Colorado; and Coni Sanders, daughter of Dave Sanders, killed in the 1999 Columbine High School shootings in Colorado.
(6) That remains to be seen.” The Aurora Australis travelled through heavy ice towards open water.
(7) In private, Remington managers advanced an argument common to American gun-owners: events such as Newtown or the cinema shooting in Aurora, Colorado, earlier this year, however tragic, are primarily a failure of mental health care.
(8) Two survivors of the 2007 Virginia Tech shooting, where 32 people died, were present, as well as the stepfather of an Aurora, Colorado, massacre victim.
(9) The acting director of the Australian Antarctic division of the department of environment, Jason Mundy, said the rescue was carried out without a hitch and it was a relief to have all passengers on board the Aurora Australis.
(10) "While Operation Aurora shed light on advanced threats from sponsored adversaries, the number of compromised companies and organisations pales in comparison to this single botnet," said Amit Yoran of NetWitness.
(11) That did not stop Tyrek and his mother from riding the bus to Washington with the Newtown Action Alliance to join forces with families of gun violence from Chardon, Aurora, Hartford, Chicago, Tucson, and Virginia Tech and to talk to lawmakers about ways to reduce gun violence.
(12) Elle Fanning will play Aurora as a teenager and the cast also includes Sharlto Copley, Miranda Richardson, Sam Riley and Imelda Staunton.
(13) Aurora Energy Research has also forecast that the price of power will decline to £46 per MWh by 2020 on the back of reduced demand, more windfarms and lower gas prices.
(14) Ten non-profits in the Aurora area have had funds directed to them, he went on, when the families were "certain that everyone who donated their hard-earned wages intended for 100% of the donations to go directly to the victims … Unfortunately, that does not seem to be the case."
(15) The cost of the rescue will largely fall to the ships involved – the Aurora Australis and Xue Long – and insurance.
(16) Derek Lovelock, chairman of Aurora Fashions, the owner of Oasis, says Schaffer did a great job on Odille.
(17) In Aurora, Planned Parenthood officials said there was an attempted arson outside the clinic’s front door on 19 July.
(18) James Holmes, a former neuroscience graduate student, is charged with killing 12 people and injuring 70 by opening fire in a darkened theater in the Denver suburb of Aurora last July.
(19) In Aurora, attention focused on the apartment in Paris Street, where Holmes lived.
(20) He travelled to Fort Hood, Texas soon after the 5 November 2009 tragedy in which 13 service members died at the hands of a fellow military member; he was in Tucson, Arizona days after the 8 January 2011 that left the Congress member Gabby Giffords shot in the head and six dead; and he was in Aurora, Colorado to mark the 20 July rampage in a cinema in which 12 people were killed.